1. Field of the Invention
The present invention relates generally to the manufacture of metal tubing for use in nuclear fuel assemblies and, more particularly, is concerned with a flying cutoff apparatus employing a cutter mechanism capable of clamping to and riding with longitudinally moving and axially rotating tubing for cutting the same to desired lengths without requiring separate components to clamp to or move the cutter mechanism with the moving and rotating tubing.
2. Description of the Prior Art
One conventional technique for manufacturing zirconium tubing for nuclear fuel assemblies involves pilgering a length of stock tubing to produce an approximately sixty-foot section having precise dimensions. Then, the section of tubing is removed from the pilgering mill and cut into twelve-foot lengths, which is the required length for use in nuclear fuel assemblies. The interim step of removing the sixty-foot sections of tubing before cutting requires additional routing and handling and greater area which is an inefficient use of labor and floor space.
Various approaches are proposed in the prior art for cutting pipe or tube to desired lengths upon emerging from a forming machine. Representative of the prior art approaches are the apparatuses disclosed in U.S. Patents to Neuman (U.S. Pat. No. 1,269,635), Gedien et al (U.S. Pat. No. 1,625,850), Fullerton et al (U.S. Pat. No. 3,076,641), Bieri (U.S. Pat. No. 3,224,310), Miyazaki (U.S. Pat. No. 3,596,549), Meyer (U.S. Pat. No. 3,662,999), McMinn (U.S. Pat. No. 3,717,058), Harris (U.S. Pat. No. 3,886,832) and Borzym (U.S. Pat. No. 4,542,670). While these apparatuses undoubtedly operate satisfactorily under the range of conditions for which they were designed, all appear to incorporate at least one of the following disadvantages. Some require independent means for moving the severing mechanism with the moving pipe or tube. Others have means separate from the severing mechanism for clamping the latter to the moving pipe or tube. Still others must be rotated to sever the pipe or tube, while others use severing techniques not appropriate for use in cutting fuel assembly tubing.
Consequently, a need still exists for a fresh approach to cutting desired tubing lengths from a moving longer section of tubing as it emerges from a forming machine, which approach will eliminate the drawbacks of these prior approaches without creating new limitations.